Dr. Eggman is one of the main antagonists of Super Smash Bros. Crossover. He is a member of the Koopa Troop and was one of the main antagonists in Season 3. Dr. Eggman reappears in Season 20 during the second arc, when Infinity Titanium Mecha Sonic sought him out after getting severly damaged by Samus Aran, and Eggman reveals that he salvaged Mecha Sonic's previous bodies to repair him. In Season 22, Dr. Eggman begins working with his younger self to increase the success of the villains. In Season 23, Dr. Eggman is betrayed by Metal Sonic, losing his ranking within the villains and most of his army. After Tikal is (apparently) released from Coredegon's grasp, Dr. Eggman offers hospitality to the Dark Heroes of Legend, but secretly intends to use them and the Infinity Sword, the remains of which were gathered by Classic Metal Sonic, to finally fufill his goal of creating the Eggman Empire. Even after the Dark Heroes of Legend leave, Dr. Eggman remains a larger threat until he is imprisoned after having a mental breakdown, where he and the other villains are ultimately abandoned by Metal Sonic. However, Dr. Eggman and the other villains break out after regaining their sanity. After the timeline is altered due to Drago's actions, Dr. Eggman becomes frustrated that they would've won in the future if Drago hadn't intervened, but later sees Scourge the Hedgehog's data about the 3 timelines, prompting Dr. Eggman to try and destroy the barriers keeping them apart, and summons Robotnik Prime from the dead as a distraction when Neon flees to warn Samus about his plan (dubbed "Operation DNA"). However, when Metal Sonic reveals Robotnik Prime's identity, Dr. Eggman reveals he is an alternate Dr. Robotnik that came to Earth-616 after Robotnik Prime died. Dr. Eggman then betrays the villains and locks them up. Despite getting help from 5 other Robotniks (Classic Eggman, Robotnik Prime, Fleetway Robotnik, Sonic '06 Eggman, and Eggman Nega), Dr. Eggman is defeated by the Heroes of Legend once again and is imprisoned with his counterparts inside the White Space. Later, Dr. Eggman and his counterparts are freed from the White Space by Scourge and Metal Sonic, due to the need for a Dr. Robotnik in the prime universe. Dr. Eggman then proceeds to ressurect Coredegon, Slycerak, Exostriker, and Mandibor, revealing that he wasn't affected by the recreation of the Smash World. In Season 25's second arc, due to being at the heart of the multiversal reset, Dr. Eggman somehow manages to become the ruler of planet Earth, though his reign is short lived since the Earth is destroyed due to being unstable. In Season 32, Dr. Eggman activates his Evil Exposure Machine to reveal who is corrupted on Earth and destroys it afterwards so that his act cannot be undone. Dr. Eggman also has Mephiles the Dark roboticize Sally Acorn once again. After suffering another defeat at Sonic's hands, Eggman becomes desperate to destroy Sonic forever, and ambushes him with his counterparts on the Egg Carrier. Despite his best efforts, Dr. Eggman is defeated by the combined might of Hyper Sonic, the defective Mecha Sally, and the Final Color Blaster. However, Dr. Eggman refuses to give up, and he decides to battle Sonic with his own strength. It is subsequently revealed that Dr. Eggman, in addition to being an alternate Dr. Robotnik, is actually a robot himself. Midway through the battle, however, Rosalina shows up and electrocutes Dr. Eggman before teleporting him away. After Rosalina is defeated, Dr. Eggman returns without any explanation, but rather than resume the fight, he asks that Sonic finishes him off, as he realized he cannot beat Sonic no matter what he does. Dr. Eggman's wish is fufilled, as Sonic kills Dr. Eggman to put an end to their conflict. In Season 33, Dr. Eggman is ressurected and rebuilt by the heroes to combat Sonic, who has become convinced that the only way to achieve peace is through force. In Season 34, Dr. Eggman goes into hiding after Mecha Sally steals his army, and sides with the League of Villains during The Dimensional War until Midna unleashes the Midna Virus, where he decides to join Mecha Sally's army to preserve his life.
Dr. Eggman was loyal to the villains in Seasons 1-22. In Season 23, after being upstaged by Metal Sonic, Dr. Eggman begins acting independently due to gaining the trust of the Dark Heroes of Legend, but soon starts working with the other villains once again.
However, Dr. Eggman is a cruel and manipulative villain, who will not hesitate to kill his enemies to achieve his goals. Following another defeat at Sonic's hands, Dr. Eggman becomes demented and deranged, determined to kill Sonic. However, after Rosalina's defeat, Dr. Eggman realizes he can never beat Sonic no matter what, which is why he was content with Sonic killing him.
EggDrago- Dr. Eggman's first vehicle used in Season 2. It is obviously a parody of Drago. It was destroyed by Vegeta.
EggRaytheus- Dr. Eggman's second vehicle used in Season 2. It is a parody of Raytheus.
Egg Breaker- Dr. Eggman's first vehicle of Season 3. It is from Shadow the Hedgehog.
Time Eater- Formerly a malevolent entity. Dr. Eggman has since converted Time Eater into a machine that both he and his younger self pilot. It has been destroyed multiple times, but has been repaired by Dr. Eggman again and again.
Egg Emperor- One of Modern Eggman's signature vehicles. Dr. Eggman shares this machine with Metal Sonic. This vehicle is from Sonic Heroes
Egg Dragoon- One of Modern Eggman's favorite vehicles. It is from Sonic Unleashed.
Egg Destroyer- Dr. Eggman's ultimate machine introduced in Season 32. Unlike other machines, Dr. Eggman is actually fused to the Egg Destroyer.
Classic Eggman is the younger version of Dr. Eggman. Classic Eggman first appeared in Season 22 to help his older self repair the Time Eater, and has assisted him in other projects since. Classic Eggman's signature vehicle is the Death Egg Robot.
Dreamcast Eggman is Dr. Eggman as he appeared during Sonic Adventure 2: Battle. Dreamcast Eggman first appears in Season 23 where he is accused of kidnapping Dreamcast Tails and stealing the Master Emerald by Dreamcast Sonic, Dreamcast Shadow, and Dreamcast Knuckles. However, before a fight can commence, the League of Villains arrive hoping to recruit Dreamcast Eggman to their side, and demonstrate their power by overwhelming Dreamcast Sonic and Dreamcast Shadow. However, the assault is thwarted by Sonic and Shadow, who save their Dreamcast era counterparts and leave. Despite this, Dreamcast Eggman joins the villains to destroy Dreamcast Sonic.